Microelectronic ignition method and ignition module with ignition spark burn-time prolonging for an internal combustion engine

Abstract

An electrical ignition for internal combustion engines having coils and a magnetic generator that rotates synchronously with the engine. The generator's magnetic field passes periodically through the coils and induces a sequence of corresponding alternating-voltage half-waves. These charge an energy-storage element, that is discharged by actuation of an ignition switch to trigger an ignition spark and they form the voltage supply of a microelectronic and/or programmable control that actuates the ignition switch in an ignition time instant as a function of the detected half-waves and/or of a rotational state of the engine. Within one rotation, there is chosen, for the triggering of the ignition spark to prolong its burn-time, a time interval in which the primary and/or secondary coil winding is influenced by one of the half waves and the amount or range of the magnetic flux change used to prolong the burn-time is greatest within the respective sequence.

What is claimed is:  
     
       1. An electrical ignition method for internal combustion engines using an arrangement of a plurality of coils and of a magnetic generator that rotates synchronously with the engine and whose magnetic field at the same time flows periodically through the coils and generates therein a sequence of magnetic flux changes per rotation, a sequence of corresponding alternating-voltage half-waves being induced in the coils that are used: 
       to charge an energy-storage element, that is discharged by actuation of an ignition switch via a primary-coil winding of an ignition transformer to trigger an ignition spark, and  
       to form a voltage supply for a microelectronic control that is used to actuate an ignition switch in an ignition time instant as a function of the alternating-voltage half-waves detected or of the state of the internal combustion engine,  
       wherein, within one rotation, there is chosen, for the triggering of the ignition spark to prolong its burn-time, such a time interval in which the a coil winding is specifically influenced by one of the magnetic flux changes and the magnetic flux change used to prolong the burn-time is greatest within the respective sequence. 
     
     
       2. An electrical ignition method for internal combustion engines, as claimed in  claim 1 , using an arrangement of a plurality of coils and of a magnetic generator that rotates synchronously with the engine and whose magnetic field at the same time flows periodically through the coils and generates therein a sequence of magnetic flux changes per rotation, a sequence of corresponding alternating-voltage half-waves being induced in the coils that are used: 
       to charge an energy-storage element, that is discharged by actuation of an ignition switch via a primary-coil winding of an ignition transformer to trigger an ignition spark, and  
       to form the voltage supply for a microelectronic control that is used to actuate the ignition switch in an ignition time instant as a function of the alternating-voltage half-waves detected or of the state of the internal combustion engine,  
       wherein, within one rotation, there is chosen, for the triggering of the ignition spark to prolong its burn-time, such a time interval in which the coil winding is specifically influenced by one of the magnetic flux changes, use of the alternating voltage half-waves in this time interval being excluded at least for the formation of the voltage supply. 
     
     
       3. An ignition method as claimed in  claim 2 , wherein, in said time interval, use of the alternating-voltage half-waves is excluded for the charging of the energy-storage element. 
     
     
       4. An ignition method as claimed in  claim 1  or  claim 2  or  claim 3 , with use of a coil arrangement extending constructionally and geometrically over a first and a second limb, its first and then its second magnetic pole being moved past, within one rotation of the magnetic generator, in each case consecutively the first and then the second limb, wherein the magnetic flux change occurring at a third position in time per rotation or sequence in the second limb is fed directly to the ignition transformer and, in the process, being used to prolong the ignition spark burn-time. 
     
     
       5. An ignition method as claimed in  claim 4 , wherein the alternating voltage half-waves across assigned coils occurring in the first and second limb per rotation or sequence in each case at the second position in time are used substantially simultaneously to charge the energy storage element and for the purpose of voltage supply to the control. 
     
     
       6. An ignition method as claimed in  claim 4 , wherein, to form the voltage supply, one of the alternating voltage half-waves of the second limb is used within the respective rotation or sequence in that time interval in which the magnetic flux change having the greatest magnitude occurs in the first limb and is available to be used to charge the energy-storage element. 
     
     
       7. An ignition method as claimed in  claim 4 , wherein, to form the voltage supply, those alternating voltage half-waves are used that originate from the magnetic flux changes that occur in the second limb and within the respective rotation or sequence therein at the second or fourth position in time of the respective sequence and with the second-largest or third-largest magnitude. 
     
     
       8. An ignition method as claimed in  claim 4 , wherein alternating voltage half-waves of the coils both of the first and of the second limb are fed to the control for processing and, in this process, are placed in time relationship with respect to one another, from which the control determines direction of rotation, rotational position or rotational speed of the magnetic generator for the purpose of adjusting and triggering the ignition time instant. 
     
     
       9. An ignition method as claimed in  claim 4 , wherein the ignition time instant, in a rotational-speed range corresponding to the starting of the internal combustion engine, is triggered by the control within a time interval that corresponds as a maximum to a rotation of the magnetic generator through roughly 80 degrees. 
     
     
       10. An ignition method as claimed in  claim 4 , wherein, within the respective sequence, the ignition time instant is triggered within a time interval that is defined by the magnetic flux change having the greatest magnitude within the sequence and also by a respective subsequent magnetic flux change. 
     
     
       11. An ignition method as claimed in  claim 4 , wherein, at least twice per rotation, the control is reset synchronously at predetermined positions of the magnetic generator or of the internal combustion engine to an initial state and, in this process, a control time counter is started in each case whose counting results are correlated with the occurrence in time of alternating voltage half-waves detected by the control, from which direction of rotation, rotational position or rotational speed of the magnetic generator are determined by means of the control for the purpose of adjusting the ignition time instant. 
     
     
       12. An ignition method as claimed in  claim 11 , wherein the corresponding reset signals are derived from alternating voltage half-waves that are at the second or fourth position in a sequence and are used to form the voltage supply. 
     
     
       13. An ignition method as claimed in  claim 11 , wherein a respective second reset signal within a sequence is triggered at a rotational position that corresponds to a rotational angular range of roughly 15 degrees before and 10 degrees after top dead center of the internal combustion engine and a respective first reset signal within a sequence corresponds to a rotational angular range of 50 to 70 degrees prior to the respective second reset signal. 
     
     
       14. An ignition method as claimed in  claim 1 , in which, within one rotation of the magnetic generator, its first and then its second magnetic pole is moved past the charging coil used to charge the energy-storage element and, in the process, a sequence of four alternating voltage half-waves is generated in the charging coil, wherein both the last alternating voltage half-wave of the respective sequence and the largest alternating voltage half-wave of the next sequence are used to charge the energy-storage element. 
     
     
       15. An ignition module, having a magnetizable yoke core that is surrounded by a plurality of induction coils and that has at least a first limb surrounded by a charging coil and a second limb surrounded at least by primary and secondary coils of an ignition transformer having an energy-storage element that is connected to the charging coil and that can be discharged by means of an ignition switch via a primary-coil winding of the ignition transformer to trigger an ignition spark, wherein a microelectronic control is connected to the coils for sampling, processing and rating the alternating voltage half-waves of the latter and is designed to actuate the ignition switch as a function of the alternating voltage half-waves, an input of the control being connected to a coil of the second limb via a rectifier for the purpose of its voltage supply. 
     
     
       16. An ignition module as claimed in  claim 15 , wherein a separate voltage-supply coil is mounted on the second limb for the purpose of supplying the rectifier for the control. 
     
     
       17. An ignition module as claimed in  claim 16 , wherein the separate voltage-supply coil is constructed with a wire of the same electrical resistance as the secondary coil of the ignition transformer. 
     
     
       18. An ignition module as claimed in  claim 16  or  17 , wherein the voltage-supply coil is mounted in the end region of the second limb. 
     
     
       19. An ignition module as claimed in  claim 15 , wherein the control is connected for the purpose of signal sampling via one input in each case to coils both of the first and second limb for the purpose of processing their alternating voltage half-waves. 
     
     
       20. An ignition module as claimed in claims  19 , wherein the signal sampling inputs detect alternating voltage half-waves both the charging coil on the first limb and of the voltage-supply coil, connected to the rectifier on the second limb. 
     
     
       21. An ignition module as claimed in  claim 19  or  claim 20 , wherein a signal-level attenuation circuit is connected upstream of the signal sampling inputs of the control. 
     
     
       22. An ignition module as claimed in  claim 21 , wherein the attenuation circuit comprises a resistor network that is combined with binary port terminals of the microelectronic control to form a programmable voltage divider. 
     
     
       23. An ignition module as claimed in  claim 15 , wherein a reset circuit is connected to at least one coil of the second limb and is designed to respond to the second and fourth alternating voltage half-waves of a sequence.